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Ontario · climate station 6158733 · 173.4 m

Toronto Lester B. Pearson Int'l A

Average last spring frostApril 30
Average first fall frostOctober 16
Frost-free period168 days

1981–2010 normals; ECCC quality code “A” (A = WMO “3 and 5 rule”; B ≥ 25 years; C ≥ 20 years; D ≥ 15 years of data). An average is not a guarantee: a late frost is still possible.

Probabilities

10%25%33%50%66%75%90%
Spring frost (0 °C or lower) on or afterMay 19May 13May 10May 4April 29April 28April 16
Fall frost on or beforeSeptember 22September 29October 3October 9October 16October 19October 28
Frost-free period ≤ (days)134142149155165170185

Example: the spring 10% column is the date after which a frost occurs in only one year in ten.

Indicative planting calendar

Start tomatoes, peppers and eggplant indoorsMarch 5 – March 19
Sow peas, spinach, lettuce and radish outdoors (frost-tolerant)April 2 – April 16
Plant potatoes and onion setsApril 16 – April 30
Transplant tomatoes and peppers; sow beans, corn, squash and cucumbersMay 7 – May 21
Last sowing of quick crops (radish, lettuce, spinach)September 1 – September 16
Harvest or cover frost-tender cropsOctober 9 – October 16
Plant garlic and spring bulbsOctober 16 – November 13

General gardening rules of thumb computed from this station's average last/first frost dates; they are not ECCC data. Adjust to local conditions and seed-packet instructions.

Nearby stations

Toronto · 203 dRichmond Hill · 157 dToronto Buttonville A · 157 dKing Smoke Tree · 155 dCookstown · 130 dMillgrove · 147 d
Sources & licences

Environment and Climate Change Canada — Canadian Climate Normals 1981–2010 (station data, MSC Datamart) (30-year averages; not updated). Retrieved 2026-10-18 19:11 UTC.
Data Source: Environment and Climate Change Canada Environment and Climate Change Canada Data Servers End-use Licence.

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